首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   163702篇
  免费   2792篇
  国内免费   1395篇
教育   106102篇
科学研究   22989篇
各国文化   2180篇
体育   11986篇
综合类   2874篇
文化理论   1213篇
信息传播   20545篇
  2022年   1015篇
  2021年   2230篇
  2020年   2559篇
  2019年   2993篇
  2018年   3500篇
  2017年   3823篇
  2016年   3881篇
  2015年   3900篇
  2014年   5659篇
  2013年   30303篇
  2012年   5865篇
  2011年   6606篇
  2010年   5965篇
  2009年   5805篇
  2008年   5495篇
  2007年   5684篇
  2006年   5908篇
  2005年   5101篇
  2004年   4427篇
  2003年   3633篇
  2002年   3347篇
  2001年   3095篇
  2000年   2345篇
  1999年   2233篇
  1998年   1981篇
  1997年   1874篇
  1996年   1986篇
  1995年   1666篇
  1994年   1648篇
  1993年   1612篇
  1992年   1560篇
  1991年   1425篇
  1990年   1360篇
  1989年   1295篇
  1988年   1142篇
  1987年   1049篇
  1986年   1104篇
  1985年   1254篇
  1984年   1119篇
  1983年   1050篇
  1982年   1056篇
  1981年   986篇
  1980年   949篇
  1979年   1004篇
  1978年   1008篇
  1977年   936篇
  1976年   837篇
  1975年   672篇
  1974年   664篇
  1973年   638篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
21.
[目的/意义] 通过构建二模复杂网络模型,揭示隐藏在海量文献中的隐性知识。[方法/过程] 通过NetworkX复杂网络工具包,依据任意两个节点的共现关系构建二模复杂网络模型;对网络模型中节点的共现关系进行加权,计算网络的拓扑信息并进行AP聚类,提取节点间的直接关系;采用AUC方法对AA、JC、加权改进的wAA和wJC等4种链路预测算法进行评价,遴选出最合适的预测算法,并对复杂网络的隐性关系进行预测分析。[结果/结论] 以潜在药物靶点挖掘为例进行的实证研究结果表明,wAA链路预测算法为最优的链路预测算法;二模复杂网络模型、指标和方法体系在美国化学文摘社数据库中的药物靶点挖掘中具有一定的有效性。下一步计划在其他数据库中或其他研究领域中进行尝试,以进一步验证该模型的通用性和有效性。  相似文献   
22.
ABSTRACT

Olfaction has been described as one of the least studied of the senses. This has certainly proven true in Communication. This project applies Ethnography of Communication and Cultural Discourse Analysis to examine the role that olfaction plays in the cultural meaning systems of two speech communities: residents surrounding the Gowanus Canal and bereaved parents. The cultural hub used to explore the cultural significance of olfaction in both speech communities is feeling. The analyses illustrate how emotions are tied to associated sensations and further become activated through radiants of dwelling, relating and acting. The analysis also shows how olfaction may serve to unify and separate members of a community. The significance of this research encourages stretching the boundaries of communication studies by examining the less studied physical senses and the boundaries of Cultural Discourse Analysis by providing distinctions that others can incorporate when examining feelings.  相似文献   
23.
The emerging creative practices of digital collections are increasing in prominence thanks to the access to, and appeal of, data visualizations. Interactive data visualizations, such as a map, timeline, chart, graph, or artist’s rendering of data, enable users to pursue their own research interests within a collection and participate in new areas of research. Use of these data visualizations enhances the scope of the collection and enables a modern and diverse thematic collection to emerge. This article considers the question: Does the addition of data visualizations affect how users participate with a research collection? Impacts on collection development, application of user-centered design, and analysis of users’ exploratory strategies are discussed. Examples of data visualizations used in digital humanities projects and digital collections are presented as case studies.  相似文献   
24.
教材史料简言之即是教材中的史料,部编教材《中外历史纲要》的显著特点是纲要式的正文配以形式多样、种类丰富的史料。纲要式体裁决定了正文非常简练,是对历史脉络的勾画,这种勾画对于高中生学习历史来说未免枯燥、单一。好在部编教材配以丰富的史料,这些教材史料正好弥补了教材正文的简练,使历史学习变得有血有肉。  相似文献   
25.
Cultural Studies of Science Education - The retention of underrepresented students remains a significant challenge in the STEM (Science, Technology, Engineering and Math) disciplines. A broad range...  相似文献   
26.
27.
In this digital ITEMS module, Dr. Jeffrey Harring and Ms. Tessa Johnson introduce the linear mixed effects (LME) model as a flexible general framework for simultaneously modeling continuous repeated measures data with a scientifically defensible function that adequately summarizes both individual change as well as the average response. The module begins with a nontechnical overview of longitudinal data analyses drawing distinctions with cross-sectional analyses in terms of research questions to be addressed. Nuances of longitudinal designs, timing of measurements, and the real possibility of missing data are then discussed. The three interconnected components of the LME model—(1) a model for individual and mean response profiles, (2) a model to characterize the covariation among the time-specific residuals, and (3) a set of models that summarize the extent that individual coefficients vary—are discussed in the context of the set of activities comprising an analysis. Finally, they demonstrate how to estimate the linear mixed effects model within an open-source environment (R). The digital module contains sample R code, diagnostic quiz questions, hands-on activities in R, curated resources, and a glossary.  相似文献   
28.
29.
Children are sensitive to a number of considerations influencing distributions of resources, including equality, equity, and reciprocity. We tested whether children use a specific type of reciprocity norm—market norms—in which resources are distributed differentially based strictly on amount offered in return. In two studies, 195 children 5–10 years and 60 adults distributed stickers to friends offering same or different amounts of money. Overall, participants distributed more equally when offers were the same and more unequally when offers were different. Although sensitive to why friends offered different amounts of money, children increasingly incorporated market norms into their distributions with age, as the oldest children and adults distributed more to those offering more, irrespective of the reasons provided.  相似文献   
30.
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号